The University of Miami/Jackson Memorial Hospital Departments of Pediatrics, Obstetrics and Gynecology, and Radiology have demonstrated excellence in performing clinical investigations involving numerous maternal-fetal, neonatal, and pediatric problems. Investigators within these departments are conducting numerous research studies funded by the National Institutes of Health, National Institute on Drug Abuse, and the National Institute of Mental Health. In most cases, the described projects relate directly to the timely topics of perinatal cocaine exposure and perinatal human immune deficiency (HIV-1) infection. State-of-the-art ultrasound equipment with excellent capabilities for real-time imaging and color-flow Doppler assessments would enhance the dimensions of currently funded projects and provide exciting new directions. The proposed system is optimally configured and fully capable of meeting present as well as future requirements of the major users of this application. This proposal discusses the specific applications of the requested equipment by PHS-funded investigators within the Divisions of Neonatology (Dr. Emmalee S. Bandstra and Dr. Charles R. Bauer), the Division of Maternal-Fetal Medicine (Dr. Mary Jo O'Sullivan), the Division of Pediatric Nephrology (Dr. Jose Strauss), the Division of Pediatric Infectious Disease (Dr. Gwendolyn Scott), and the Division of Psychology (Dr. Tiffany Field, Dr. Kim Oller, and Dr. Rebecca Eilers). This system would also facilitate projects within the General-Clinical Research Center (Dr. Adel Yunis). The equipment will be stationed in the East Tower of Jackson Memorial Hospital in the Neonatal Research Laboratory immediately adjacent to the Neonatal Intensive Care Unit and Labor and Delivery. Since the equipment is portable, ultrasonographic examinations can be performed at the patient's bedside, in outpatient examination rooms, or in investigators' laboratories. A full-time ultrasonography technologist will be responsible for scheduling routine equipment maintenance, quality control, and communicating with the Principal Investigator and the Advisory Council regarding scheduling priorities. Dr. Berta Montalvo (Director of Body Ultrasound), Dr. Pedro Ferrer (Director of the Pediatric Echocardiography Laboratory), and Dr. Suman Hariharan (Associate Professor of Maternal-Fetal Medicine) will provide specific assistance with the technical and interpretive elements of the ultrasonographic studies involving their specific areas of expertise.